Data collections including suspended load, bed load, bed material and flow discharge have been carried out during the Study (Ibrahim 2002, Darus 2002, Abdul Ghaffar 2003, Sinnakaudan 2003). A total of 122 set of data have been obtained for the period from September 2000 until October 2002. The analysis also includes Yahaya (1999) and Ariffin (2002) study for Kerayong River, Kulim River and Langat River catchment (224 sets of data). Table 1 below shows the summary of the sediment transport assessment for the 122 and 346 sets of data. Figure 2 shows the relationship between transport and flow parameter of the total 346 data. Comparison with Graf equation shows that the Malaysian sediment transport data consisting of mainly coarse sand agrees well with the equation. However, for fine sand, the modified Graf equation seems to suit better:

(1)

where

Ss is the specific gravity of sediment, d50 the mean sediment size, R the hydraulic radius, So the water surface slope, V the mean flow velocity, Cv the volumetric concentration and g the gravity acceleration.

Attempts were also made to derive new equations for computing Manning n for application to the moderate-size and sand-bed streams in Malaysia based on 168 data collected from Kinta, Langat and Kulim Rivers. The resulting equations (Ab. Ghani et. al 2007, Chang 2006, Soong 2009) have an error less than 10% in predicting flow discharge for all the measured data. Both equations have a regression coefficient R2 = 0.86: